Requirement of ginkgo pollen-derived tissue cultures for boron and effects of boron deficiency.

Ginkgo biloba L. pollen-derived tissue, which is made up of small, friable masses of homogeneous parenchymatous cells, was shown to require boron in the culture medium. If no boron is supplied, growth soon stops. Growth responses to additions of boron were observed up to an optimum level of 0.1 mg of boron per liter.Histological examination and chemical analyses showed 2 general effects of boron deficiency: (1) a reduced rate of cell division, with no significant effect on cell size, and (2) some alteration in composition of the cell walls. With the exception of a reduction in fructose, the concentration of soluble and of readily hydrolyzable carbohydrates, and the concentration of protein in the tissue, were not affected by boron deficiency.